monochrome y12 image format not supported

[fiepfiep]

Hello, I am using a mira220 image sensor.
I compiled my own v4l2 driver and libcamera to support this sensor.
see here:
https://github.com/ams-OSRAM/mira220_v4l2_driver/blob/main/mira220.c
for some reason, I can get the Y10 monochrome format to work but not the Y12.
When using RGGB color format, everything works.
Is this supported by libcamera?

pi@raspberrypi:~ $ LIBCAMERA_LOG_LEVELS=RPI:0,Camera:0 rpicam-hello
[0:02:19.828096425] [1346]  INFO Camera camera_manager.cpp:340 libcamera v0.0.0+6145-f659d2f3-dirty (2026-04-28T20:23:59CEST)
[0:02:19.828452080] [1347] DEBUG Camera camera_manager.cpp:74 Starting camera manager
[0:02:19.845445986] [1347] DEBUG Camera camera_manager.cpp:143 Found registered pipeline handler 'rpi/pisp'
[0:02:19.845606499] [1347] DEBUG RPI pisp.cpp:891 Unable to acquire a CFE instance
[0:02:19.845652961] [1347] DEBUG Camera camera_manager.cpp:143 Found registered pipeline handler 'rpi/vc4'
[0:02:19.856183512] [1347]  INFO IPAProxy ipa_proxy.cpp:180 Using tuning file /usr/local/share/libcamera/ipa/rpi/vc4/mira220_mono.json
[0:02:19.859528398] [1347]  INFO Camera camera_manager.cpp:223 Adding camera '/base/soc/i2c0mux/i2c@1/mira220@10' for pipeline handler rpi/vc4
[0:02:19.859637395] [1347]  INFO RPI vc4.cpp:445 Registered camera /base/soc/i2c0mux/i2c@1/mira220@10 to Unicam device /dev/media2 and ISP device /dev/media1
[0:02:19.859694319] [1347]  INFO RPI pipeline_base.cpp:1117 Using configuration file '/usr/local/share/libcamera/pipeline/rpi/vc4/rpi_apps.yaml'
[0:02:19.859888405] [1347] DEBUG Camera camera_manager.cpp:164 Pipeline handler "rpi/vc4" matched
[0:02:19.859929829] [1347] DEBUG RPI vc4.cpp:192 Unable to acquire a Unicam instance
[0:02:19.859954828] [1347] DEBUG RPI vc4.cpp:192 Unable to acquire a Unicam instance
Made X/EGL preview window
Made DRM preview window
Preview window unavailable
[0:02:19.895525920] [1347] DEBUG RPI pipeline_base.cpp:968 Format: 1600x1400 fmt R12 Score: 0 (best 0)
[0:02:19.895657805] [1346] DEBUG Camera camera.cpp:1150 streams configuration: (0) 1600x1400-R12_CSI2P/RAW
[0:02:19.895842502] [1347] DEBUG RPI pipeline_base.cpp:968 Format: 1600x1400 fmt R12 Score: 0 (best 0)
[0:02:19.895912963] [1346] DEBUG Camera camera.cpp:1150 streams configuration: (0) 800x600-XRGB8888/sYCC (1) 1600x1400-R12_CSI2P/RAW
Mode selection for 800:700:12:P
    R12_CSI2P,1600x1400/0 - Score: 375
[0:02:19.896157955] [1346] DEBUG RPI pipeline_base.cpp:968 Format: 1600x1400 fmt R12 Score: 0 (best 0)
[0:02:19.896234526] [1346] DEBUG RPI pipeline_base.cpp:341 Color space changed from Unset to Unset
[0:02:19.896265729] [1346] DEBUG RPI pipeline_base.cpp:286 Try color space sYCC
Stream configuration adjusted
[0:02:19.896333615] [1346] DEBUG RPI pipeline_base.cpp:968 Format: 1600x1400 fmt R12 Score: 0 (best 0)
[0:02:19.896374632] [1346] DEBUG RPI pipeline_base.cpp:341 Color space changed from Unset to Unset
[0:02:19.896402520] [1346] DEBUG RPI pipeline_base.cpp:286 Try color space sYCC
[0:02:19.896430575] [1346] ERROR Camera camera.cpp:1203 Can't configure camera with invalid configuration
ERROR: *** failed to configure streams ***

[naushir]

Right now this is not supported by our libcamera implementation. This should be fairly straightforward to implement though, but we are not able to test it since we don't have sensors that have this mode. Are you in a a position to provide patches that would implement this once you've tested with your sensor?

[fiepfiep]

Someone already did the work..
not sure what is still missing in the code?
https://lists.libcamera.org/pipermail/libcamera-devel/2024-August/044023.html

[naushir]

That seems to be me 😄

I cannot remember this patch at all. I'll see what I can debug, but it might be limited without a sensor that supports this mode.

[fiepfiep]

Could you give me some debug instructions?
Otherwise I can ship you some HW.

[naushir]

Are you able to use a debugger and step through the code in RPiCameraConfiguration::validate():

libcamera/src/libcamera/pipeline/rpi/common/pipeline_base.cpp

Line 154 in fe601eb

CameraConfiguration::Status RPiCameraConfiguration::validate()

?

I believe that's where it seems to be failing.

[6by9]

I've found naushir a sensor that will run as Y12 (imx327).